The Forensic Doctor Better Than a Detective

”But everyone should have felt it; our suspicion of him is gradually deepening.”

”The next step is to slowly transform this suspicion into a solid chain of evidence — moving him from ’suspect’ to ’murderer’, and this requires support from critical trace evidence.”

Mr. Chen spoke calmly, but the pressure on his shoulders was not light.

In Mr. Chen’s many years of experience, the more brutal and fierce the crime, the more likely it is to leave behind a wealth of biological traces or physical evidence;

In contrast, in cases like this one, where the killer uses a simple and direct method to inflict a fatal wound and then quickly leaves, there are far fewer interaction traces left at the scene — a single fatal stab, a clear wound, but lacking the hair, skin debris, fibers, and other trace evidence that might result from tearing, fighting, or prolonged contact.

This is precisely the key difficulty in the investigation of this case: during meticulous early crime scene investigations, no clear traces were found that could directly link the killer to contact with the victim.

The killer is like a silent shadow, leaving only the result, but almost erasing the process.

However, Mr. Chen knows that the more a case is like this, the more patience and meticulousness are needed — the real breakthrough often lies hidden in the easily overlooked details.

After a while, Director Hou slowly nodded and added with a heavy expression: ”At present, this indeed seems to be the only feasible breakthrough.”

”Regardless of whether we can ultimately find key evidence, we must make every effort — not only to advance the case but also as a necessary explanation for the truth of the matter.”

In less than 30 minutes, a white van marked with ”Crime Scene Investigation” steadily stopped at the construction site entrance.

Before leaving, they urgently applied for a search warrant and specially contacted a skilled locksmith to accompany them.

After all, time was pressing, and attempting to obtain the excavator keys from the driver could delay the opportunity.

In criminal case investigations, technical unlocking approved through legal procedures and carried out by professionals is also a standard operational method.

Once the locksmith deftly opened the cab door of the excavator, everyone gathered around the vehicle, unconsciously turning their gaze to Jiang An — the proposer of this investigative direction, who at this moment became the center of the scene.

Chen Guan was the first to break the silence, speaking solemnly: ”Mr. Jiang, since this idea was put forward by you, you will take full command of the subsequent crime scene investigation. We will fully cooperate, and everything will go according to your plan.”

Upon hearing this, Qin Feng stepped forward as well, gently patting Jiang An on the shoulder, his voice steady and encouraging: ”Go all out, just like handling a case in Jiangcheng. Mr. Chen and I are here to support you. Whatever you arrange, we will absolutely follow.”

Hearing this, Jiang An couldn’t help but smile slightly, though there was a hint of modesty in his demeanor: ”Mr. Chen, Mr. Qin, when you put it like that, I do feel a bit of pressure.”

”Originally, I only suggested a possible direction, and now I’ve become the ’chief commander’; this transition is quite rapid.”

Director Hou, standing a little further back, also chimed in softly at this moment, his gaze carrying scrutiny and support: ”The investigation work inherently requires finding breakthroughs within the conventional framework, both adhering to principles and embracing innovation.”

”The entry point you proposed certainly has its value, it’s just that...”

He paused briefly, looking up at the silently standing excavator, its cabin door wide open like a silent riddle, ”After such a long time has passed, whether the scene still retains valuable trace evidence requires our cautious and in-depth investigation.”

Under the intense gaze of everyone, Jiang An deftly stepped forward, put on gloves, and steadily entered the cab of the excavator.

Qin Feng stood guard by the ladder next to the cab door, his gaze tightly following Jiang An’s actions, also focusing on the small and enclosed interior space.

The cab’s interior was extremely simple, consisting only of an oil-stained mechanical gear lever and a severely worn leather seat, with nothing unusual upon first glance.

Yet, the moment the cabin door opened, a strong and acrid smell of engine oil hit them, quickly permeating the surrounding air.

With a serious expression, Jiang An held a high-intensity flashlight, slowly moving it from the rust-stained gear lever to the seat, and then carefully scanning back and forth between the seat and the lever several times.

As time ticked by, he maintained this position for a long time but still failed to discover any suspicious traces.

His sight finally settled on the metal floor beneath his feet — due to its reflective material and smooth surface, no clear footprints were left visible to the naked eye.

Although Jiang An had a background in forensic medicine with some understanding of trackology, he was aware that his knowledge was inadequate for professional identification.

After a moment of contemplation, he turned and said toward the door: ”Please have the colleagues responsible for trace evidence and footprint examination come up and focus on fingerprint analysis.”

After speaking, he carefully exited the cab, steadily descending the ladder.

Soon, the fingerprint expert from Guangling City’s criminal investigation team responded and stepped forward.

This was a middle-aged man in his forties wearing thin-framed glasses, neatly dressed, his demeanor meticulous, exuding professionalism and precision in every move.

Carrying an investigation case, he ascended the ladder under everyone’s watchful eyes, entering the cab.

Following the focus areas previously pointed out by Jiang An, he first concentrated his attention on the gear lever and the side handles, using a magnifying glass and special light sources to meticulously examine the traces of possible contact inch by inch.

All personnel waiting below — including Vice Director Chen, Director Hou, and several investigators — looked up and waited intently, the air filled with tense anticipation, each hoping he could extract valuable clues from this crucial spot.

Twenty minutes later, the middle-aged expert finally straightened up, gently adjusting his glasses that had slipped down to the middle of his nose, and solemnly reported: ”Mr. Chen, Director Hou, I have conducted a comprehensive examination of the gear lever inside the cab.”

”Due to the gear lever itself being ovoid, fingerprints easily slide and distort during operation, resulting in poor continuity and blurred feature points. At present, it does not meet the conditions for a match.”

He paused slightly then continued, ”Furthermore, several fingerprints were found on the left window frame. Based on the direction and distribution, they appear to belong to the same person, and their form and height match the marks formed by a driver’s hand resting on the window during long operations.”

”These fingerprints are relatively clear and can be used for further comparison, but initial judgment indicates they are remnants of normal operation, likely unrelated to the case.”

Upon hearing this, Chen Guan nodded, and said: ”Thank you for your hard work, Mr. Li.”

”Besides what has been mentioned, are there any other findings?”

Mr. Li straightened up, slowly shaking his head: ”Not for now.”

”You know, with machinery like excavators, the operators usually only come into contact with parts like levers and control knobs during daily operations.”

”Moreover, with the constant hand movement and gripping during operations, the traces formed are often blurry and overlapping, making it difficult to extract clear and complete fingerprints.”

”However, based on the types of traces currently extracted, it can be generally determined that they all originate from the same person.”

He paused for a moment, his tone more confident, ”At least, among the fingerprints I’ve found so far, there are no features indicating the presence of a second person.”

”The marks left on all operational positions, based on direction, force, and residue, are consistent with those formed by the same person during continuous operations.”

Yet just as he was about to turn and leave, his gaze inadvertently swept over the upper part of the glass interior near the door handle.

His movement suddenly halted, bending closer.

”Wait—” he raised his hand, ”this position... has a fingerprint, very faint, not easily noticeable.”

As he spoke, he reopened the investigation lamp, the oblique light beam shining on the glass, revealing a faint fingerprint under the light.

”It seems somewhat different,” he continued, his tone growing serious, ”the fingerprint in the index finger area is of a whorl pattern, not the more common loop pattern.”

”From the shape and ridge structure, it’s markedly different from the ones discovered earlier.”

When these words fell, it seemed as if the breathing of everyone inside and outside the cab paused for a moment.

Next, a suppressed excitement spread through the air.

Everyone understood — while a fingerprint on the outside of the glass might be explained as incidental contact, the one on the inside, particularly in an area difficult to reach after the car door is closed, could only indicate that the person who left this fingerprint had indeed entered this enclosed cab.

Chen Guan stepped forward and said: ”Mr. Li, if this fingerprint, after comparison, indeed belongs to the suspect Li Xu... then you have certainly rendered great service this time!”

”Forget everything else; I will personally apply to the higher-ups to award you a second-class merit!”